Portable tooth whitening device



FIG. 1 is a reduced perspective view of the portable tooth whitening device showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a right side view thereof.

The broken lines shown in the figures are included for the purpose of illustrating portions of the portable tooth whitening device and form no part of the claimed design. 

CLAIM The ornamental design for a portable tooth whitening device, as shown and described. 